http://www.dogfoodadvisor.com/dog-food-reviews/natures-domain-dog-food/ is really good for breaking down ingredients…..I mean they categorize tons of different brands fairly well and explain how they came to that conclusion. Costco has some cheap "good" options so I hear. It really is worth it to invest in a high protein (and high fiber) food; I only feed my 37 lb. dog a little less than half a cup of taste of the wild twice a day, and my 21 lb. dog gets 1/4 cup x 2 times a day. My little dog had ribs showing until I switched her from the corn based diet her breeder had her on to TOTW. Not to mention she was crapping like a million times a day, and had absolutely disgusting skin. Corn is absolutely terrible - goes right through them and they end up looking really skinny but real 'grain's are notorious for causing allergies. ......
With just my 37 lb. dog and a 30ish lb bag of taste of the wild ($ 55 dollars here in Alaska, so cheaper elsewhere) lasted well into the third month. So, that's about maybe 22 bucks a month [overestimation] spent on food for one dog…..which is pretty affordable really. And, of course, most brands are cheaper in the lower states anyways, possible to find even cheaper brands that are healthier than Eukanuba.